The arcade shooter-type level in Octo Valley being missing is disappointing. It was in the trailer. The other stuff wasn't too important, but being in the Octo Valley trailer, that's not impressive. Hopefully it's added via an update.
Yeah I noticed that the 8-bit level hasn't been there so far, but being that I haven't completed Octo Valley yet, I figured it was just later on. It's a bit disappointing, but I guess not too big a deal, I've really enjoyed single player more than I thought I would.